I am currently working on
several projects emphasizing the cognitive development of L1, L2 and HL
(heritage language) learners. My methodological orientation is advanced
quantitative analysis (structural equation modeling, path analysis,
mediation analysis, etc.) and my thematic focus is vocabulary and reading
development in an additional language.

Vocabulary learning is cognitively demanding, incorporating the ability to
map meanings onto graphic forms, the ability to embed words into sentential
and discourse structures, and the ability to apply words to the real world.
In Nagy & Anderson (1984), it is reported that children may encounter up to
3,000 unfamiliar words each year when they read; a later study by Nagy and
colleagues states more specifically that American fifth-grade children may
encounter up to 10,000 unfamiliar words during reading activities over a
one-year period, a large proportion of which will be morphologically complex
(Nagy, Osborn, Winsor, & O¡¯Flahavan, 1994). Given the fact that vocabulary
acquisition is a complicated cognitive process, in this study I would like
to address how vocabulary knowledge is constructed in the group of Chinese
heritage language learners, how vocabulary knowledge contributes to literacy
acquisition and how different constructs are interwoven together to
influence literacy acquisition among Chinese heritage language learners. As
an orthographically-opaque language, oral language proficiency (mapping
between sound and meaning) in Chinese does not necessarily help learners¡¯
literacy skills. It remains unclear whether those previously-acquired
vocabulary knowledge (including oral vocabulary and print vocabulary) could
lead to the development of morphological awareness, which ultimately
improves word learning ability among Chinese heritage language learners.

II. Metalinguistic awareness in reading
acquisition

Morphological awareness (MA) is the knowledge a speaker has about the
mapping of sound to meaning in a given language and his/her understanding of
the word formation rules that guide the combination of morphemes (Kuo &
Anderson, 2006). Berko (1958) argues that MA, which is triggered by exposure
to oral and written language, begins to develop in English-speaking children
as young as four. Preschoolers are able to produce inflected words (e.g.
plurals) at an early stage. In addition, Carlisle & Fleming (2003) offer
some evidence for the development of MA among young elementary-age children.
Their findings indicate that first-grade students are able to segment words
into meaningful components, such as still-ness, but that children¡¯s
ability to extract the meaning of a morphologically-complex word does not
develop until the third grade. By third grade, children started to show
their awareness of suffixes that change grammatical roles. Numerous studies
have explored the role of MA in early literacy or biliteracy acquisition
across both alphabetic languages (e.g.,Kieffer
& Lesaux, 2008; Siegel, 2008) and morphosyllabic languages (e.g., Ku &
Anderson, 2003; Wang, Cheng, & Chen, 2006; Pasquarella, Chen, Lam, Luo, &
Ramirez, 2011). Ku and Anderson (2003) state that children who are
knowledgeable about morphology decompose unknown words to meaningful
segments--roots, prefixes and suffixes-- and then derive the meanings from
the integration of those meaningful units. MA has been found to facilitate
the development of vocabulary knowledge (e.g., Nagy & Anderson,
1984;
Kieffer & Lesaux, 2012),
by enhancing children¡¯s understanding of unknown words, and has also been
conjectured to contribute to text comprehension (Carlisle, 2000; Nagy,
Berninger, & Abbott, 2006) and reading ability (e.g., Carlisle, 1995; Nunes
& Bryant, 2006; Kieffer & Lesaux, 2008). In this study, it is hypothesized
that Chinese-specific MA enhances the development of vocabulary knowledge
and reading comprehension among Chinese-speaking second graders.
Multivariate path analysis was used to test the mediated and unmediated
effects of MA on multiple literacy outcomes (vocabulary knowledge and
reading comprehension) in a causal order.

Previous work

CHL development and
maintenance

I collected the data from Chinese
heritage language learners in Great Philadelphia area (including Wayne,
Radnor, Swarthmore, University City, and North Philly); investigated
specific linguistic (e.g morphosyntactic, semantic) attrition, transfer or
loss among heritage language learners; parents¡¯ measures to maintain
heritage languages; teachers¡¯ classroom practice and pedagogy in HL
classroom; and relevant language policy for this particular group of
bilingual speakers.